newshour, causes and treatments for blood clots; a look back at the presidential race; building jobs skills while in high school; the emancipation proclamation; and 2012 in the history books. but first, the other news of the day. here's kwame holman. >> holman: wall street rallied on the final trading day of the year, hoping for a fiscal cliff deal. the dow jones industrial average gained 166 points to close at 13,104, up 7% for the year. the nasdaq rose 59 points to close at 3019, up nearly 16% this year. nearly two dozen people died in a string of attacks across iraq today. most of the violence targeted shiite communities and police. one of the blasts rocked baghdad's karrada neighborhood, sending smoke billowing above the skyline. the car bomb went off near a tent where shiite pilgrims were gathering. five people were killed there. in syria, elite troops, along with tanks, battled to dislodge rebels from a key southern suburb of damascus.